1. Field of the Invention
The present invention relates to a method for the secured release of an electromechanically actuable parking brake which has a brake piston, which acts on a friction element and is displaceable into an actuation position in a brake calliper in which it presses the friction element against a brake disc, and a spindle/nut arrangement which is driven by an electric motor, is coaxial with respect to the central axis of the brake piston and has the purpose of mechanically locking the brake piston in the actuation position, the nut of which spindle/nut arrangement is secured against rotation and moved by a rotation of the spindle in a translatory fashion along the central axis either in abutment against the brake piston or away from the brake piston depending on the rotational direction, having the method steps:
driving of the spindle by means of the electric motor in the brake application direction until a predefined, maximum power drain, corresponding to a predefined brake application force, is reached, with simultaneous measurement of the power drain and detection of the rotational speed of the electric motor as a function of time.
2. Description of the Related Art
Such a method is known, for example, from DE 197 32 168 C2 which is incorporated by reference, which describes, inter alia, methods for actuating and/or applying and releasing an electromechanically actuable parking brake of the generic type mentioned at the beginning. However, the specified publication does not contain any indications of how an optimum distance, at which there is no risk of overheating of the interacting components, is set between the friction element or a brake lining and the brake disc.